Cytokines have been implicated in regulating antibody and inflammatory responses, however, their role in periodontal disease has not been elucidated. In the present study, we have assessed cytokine production by human gingival fibroblast (HGF) following in vitro passage, in order to determine if the morphology and profile cytokines produced different based on the number of passages. HGF cell lines were established by the explant method using non-inflamed gingival tissue and cells from passage 1-10 were studies. The number of cells were determined in confluent culture and cell morphology was examined by light microscopy. Fibroblasts from confluent cultures were examined for cytokine mRNA by RT-PCR; culture supernatants (CS) wereassessed for cytokines by ELISA. Our results showed that cells from passage 1-4 had normal fibroblast morphology, while cells in passage 5-10 were larger in size. In general the number of cells decreased from early to late passage. Fibroblasts from passages 1-10 contained message for IL-6, IL-1b, and IL-8 but not for IL-1a or TNF-a. IL-6 was detected in CS and the level decreased with increasing passage. IL-1a was present in CS from passage 2, 4 and 5, while TNF-a was detected in CS from passages 1, 2, 3, 6, 9 and 10. Our results indicated that the regulation of cytokine production, especially IL-6 by fibroblasts changes with in vitro passage. Research Experiences this year: This year I am focusing on gathering preliminary data for my research project which will be presented at my upcoming committee meeting, The objective of my study presently is to establish the cytokines produced by human fibroblasts from healthy gingival tissue. The specific preliminary aims of these studies are as follows: (1) To determine if there is a steady change in cytokine expression by fibroblasts during their passages in vitro. In this study, cytokine expression was assessed in fibroblasts following each of 10 passages. (2) To determine if there is a difference in IL-6 production by different fibroblast cell lines which were obtained from healthy gingival tissue. I will continue to refine and expand the specific aims of my thesis work, with consultation from my committee.